The nearby Whirlpool Galaxy, M51, was ISO's "first light" target on 28 November, when the telescope was opened to the sky. This image has since been reprocessed. The infrared images show regions of star formation along the galaxy's spiral arms and on either side of the nucleus.
ISOCAM observations of this source have been dicussed in the
paper "ISOCAM Mapping of the Whirlpool Galaxy (M 51)", Sauvage M. et al.
that appeared in the
ISO dedicated issue of Astronomy and Astrophysics Letters
Other papers concerning ISO observations of this source have been published;
"Far infrared mapping of the galaxies M51 and M101
with ISOPHOT", Hippelein H., et al.
"Analysis of the ISOPHOT FIR maps of M51 and
M101", Hippelein H., et al.